#include <iostream>
#include<unordered_set>
#include<mutex>
#include<thread>
#include<algorithm>
using namespace std;
int ready = 0;
void fun(int n)
{
	int* arr = new int[n];
	for (int i = 0; i < n; i++)
	{

		if (i == 0) { arr[0] = 1; }
		else
		{
			int sum = 0;
			for (int j = 0; j < i; j++)
			{
				//cout << arr[i - j] << " " << arr[j] << endl;
				if (i - j >= 0)
				{
					sum += arr[i - j];
					//cout << arr[i-j] << endl;
				}
				sum += arr[j];
				
			}
			arr[i] = sum;
		}
		//cout << arr[i];
	}
	cout << arr[n - 1];
}
int main()
{
	int n;
	cin >> n;
	fun(n);
}